Information about Anonymous P2p

An anonymous P2P computer network is a particular type of peer-to-peer network in which the users and their nodes are pseudonymous by default. The primary difference between regular and anonymous networks is in the routing method of their respective network architectures. These networks allow for unfettered free flow of information, legal or otherwise.

The P2P community's interest in anonymous P2P has increased rapidly in recent years for many reasons, including distrust of government (especially in undemocratic regimes), and digital imprimatur. Such a network may also appeal to those wishing to share copyrighted files illegally - organizations such as the Recording Industry Association of America and the British Phonographic Industry have successfully tracked and sued users on non-anonymous P2P networks.

Anonymous P2P as a misnomer

The term 'anonymous P2P' is somewhat of a misnomer. This is because by design, a network node must be pseudonymous since it must have an "address" at which it can be reached by other peer nodes in order to exchange data. However, usually this address, especially on anonymous networks, does not contain any directly identifiable information. Thus a user is highly, but not completely, anonymous. (In friend-to-friend networks, only the user's friends can know that his/her address is used to exchange files.)

When receiving data on any network it must come from somewhere and data must have been requested by someone. The anonymity comes from the idea that no one knows who requested the information as it is difficult - if not impossible - to determine if a user requested the data for himself or simply requested the data on behalf of another user. The end result is that everyone on an anonymous network acts as a universal sender and universal receiver to maintain anonymity.

If people are only universal receivers and do not send, then one would know that the information they were requesting was for themselves only, removing any plausible deniability that they were the recipients (and consumers) of the information. Thus, in order to remain anonymous, one must ferry information for others on the network.

Uses of anonymous P2P

There are many reasons for use of anonymous P2P technology; most of them are generic to all forms of online anonymity.

P2P users who wish anonymity usually do so as they do not wish to be identified as a publisher (sender), or recipient (receiver), of information. Common reasons include:

• The material or distribution is illegal or incriminating;
• material is legal but socially deplored, embarrassing or problematic in the individual's social world, or their workplace, religion, or other groups;
• fear of retribution (whistleblowers, unofficial leaks, public interest, activists who do not believe in restrictions on information or knowledge);
• censorship (local, organizational, or governmental level);
• personal privacy preferences (prevention of tracking or datamining activities, desire not to be known to have the information); and
• material and its distribution are both legal, but in high demand. Anonymous P2P may be used to distribute the network load to more efficiently download something like a new free software release.

A particularly open view on legal and illegal content is the Philosophy of Freenet.

Governments are also interested in anonymous P2P technology. The United States Navy used to finance the development of Free Haven's onion routing Tor network for politically sensitive negotiations and to aid in hiding the identity of government employees for intelligence-gathering work.

Views on the desirability of anonymous P2P

Such technology is desirable and in some cases necessary to ensure freedom of speech and the free flow of information. The claim is that true freedom of speech, especially on controversial subjects, is difficult or impossible unless individuals can speak anonymously. If anonymity is not possible, one could be subjected to threats or reprisals for voicing an unpopular view. This is one reason why voting is done by secret ballot in many democracies.

Anonymous P2P also has value in normal daily communication. When communication is anonymous, the decision to reveal the identity of the communicating parties is left up to the parties involved and is not available to a third party. Often there is no need or desire by the communicating party to be forced to reveal their identity. As a matter of personal freedom, many people do not want processes in place by default which supply unnecessary data. Such data could also be complied into histories of their activities, which, in their opinion, should be inherently controlled by the caller, not the called.

For example the current phone system transmits caller ID information by default to the other party. If one is calling to make an inquiry about a product or a time of a movie, the person called has a record of the phone number which called and therefore the name, address and the potential for more information about the person. If one were to walk into a store or up to a person on the street and make a similar inquiry all this personal information would not be involved. Anonymous P2P simply allows for a currently-existing activity in “meatspace” to now occur over a communications network.

Some friend-to-friend networks allow the user to control what kind of files can be exchanged with friends within the node, in order to stop them from exchanging files that user disapproves of.

A common ideal for anonymous peer-to-peer networks is to make it impossible to hinder the spread of information. This is typically achieved through encryption, making all kinds of information indistinguishable from each other.

Consequences of P2P anonymity

While anonymous P2P systems may support the protection of unpopular speech, they may also protect illegal activities not protected under some free speech laws, such as fraud, libel, the exchange of illegal pornography, the unauthorized copying of music and films, the planning of criminal activities, distribution of untraceable spam, or denial-of-service attacks. Critics of such systems hold that the advantages offered by such systems do not outweigh these disadvantages, and that other communication channels are already sufficient for unpopular speech.

Pornography trading is one public reason against anonymous P2P networks, and some believe that the networks aid terrorism. There are several responses to these criticisms. The first is that all information is neutral, and that it is the people acting upon the information that can be good or evil. The second is that perceptions of good and evil change (See moral panic): If anonymous peer-to-peer networks had been around in the 1950s or 1960s, they might have been targeted for carrying information about civil rights or anarchism. Furthermore, encryption is now a mature, well-known and widely-spread technology. Well-organized groups (such as government organisations, terrorist networks or organised crime) have little difficulty in securing their communications. So easily accessible anonymous P2P networks can be seen as a democratization of encryption technology, giving also the general populace access to secure communications.

Other issues include:

• If software is poorly designed, it may help facilitate pseudo-anonymous spam and DDoS attacks.
• It is difficult or impossible to uphold laws that can be broken through P2P networks. This could lead to the breakdown of intellectual property (though see digital rights management and copyright social conflict).
• With anonymous money, it becomes possible to arrange anonymous markets where one can buy and sell just about anything anonymously. For instance, Assassination markets would be a potential result of this (perhaps generating a positive feedback loop towards more social anonymity). Also note that any transfer of physical goods between two parties could compromise anonymity. Anonymous money could be used to avoid tax collection. That could lead to a movement towards anarcho-capitalism. It is highly unlikely that all transactions could be done anonymously, however, and a government could still rely on property taxes.
• It is easy to publish any information without the possibility of having the user's physical identity revealed. This could be used to openly publish information that governments forbid, like warez, software violating software patents, and child pornography. On the other hand, controversial information which a party wants to keep hidden, such as details about corruption issues, can be anonymously published.

Technical drawbacks of current anonymous P2P networks

There is a variety of drawbacks in the current design of many anonymous P2P applications and networks. One of the major ones is that it is difficult or impossible to hide the fact that the application is used, meaning that a government could simply outlaw its use to prevent the free flow of information. In countries where strong encryption is forbidden, governments have easy leverage to forbid anonymous P2P.

These drawbacks do not apply to some Friend-to-friend networks, and to anonymous P2P used on a wireless mesh network: unlike fixed internet connections, users don't need to sign up with an ISP to participate in such a network, and are only identifiable through their hardware. Even if a government were to outlaw the use of wireless P2P software, it would be difficult to enforce such a ban without a considerable infringement of personal freedoms. Alternatively, the government could outlaw the purchase of the wireless hardware itself, or require every wireless device to be registered under the owner's name. Protocols for wireless mesh networks are OLSR and the follow-up protocol B.A.T.M.A.N., which is designed for decentralized auto-IP assignment.

Pseudonymous P2P clients

• ANts P2P is a P2P file sharing system which anonymizes and encrypts traffic, and supports HTTP publishing
• Azureus, a BitTorrent client with the option of using I2P or Tor (open source, written in Java)
• Perfect Dark - a new file sharing program in Japan, possibly the successor to Share and Winny
• Entropy - a Freenet alternative
• Freenet - a censorship-resistant distributed file system for anonymous publishing (open source, written in Java)
• GNUnet - P2P framework, includes anonymous file sharing as its primary application (GNU project, written in C)
• I2P - an anonymizing network layer upon which applications can be built (open source, written in Java)
• i2phex - a Gnutella client which communicates anonymously through I2P
• imule - an emule port running under I2P network
• Marabunta - an anonymous distributed P2P network for chatting only, which uses only UDP
• MUTE - an anonymizing file sharing client. Kommute and Napshare are alternative clients
• Nodezilla - an anonymizing, closed source network layer upon which applications can be built (written in C++ and Java)
• OFF System - a P2P distributed file system through which all shared files are represented by randomized data blocks
• Rodi - a file sharing client which allows for a low degree of anonymity
• RShare - a file sharing system which anonymizes and encrypts the traffic
• Share - the successor to Winny
• StealthNet - a new branch of RShare, richer in features and heavily developed by the community
• Syndie - a content syndication program that operates over numerous anonymous and non-anonymous networks
• Tor - While Tor is not a P2P client itself, it provides a method for other P2P programs to become anonymous. It is also one of the larger research projects for anonymous networks.
• Winny - is very popular in Japan (freeware, written in C++ for Windows)

Private P2P clients

Main article: Private P2P

Private P2P networks are P2P networks that only allow some mutually trusted computers to share files. The functionality is similar to a group of private FTP servers, but the user interface is the same as most of the other P2P programs.

• Cspace - encrypted and serverless instant messenger
• PowerFolder - Private and Secure Filesharing with friends and colleges over the internet or LAN.
• Retroshare Instant Messenger Retroshare serverless Instant Messenger for anonymous Filesharing

Friend-to-friend clients

Main article: Friend-to-friend

A Friend-to-friend network is not just a group of private FTP servers. An F2F node can automatically forward a file (or a request for a file) anonymously between two "friends". When forwarding a file or a request between two friends, the node doesn't tell any of them who is the other and what is the other address. Then these friends' nodes can in turn forward anonymously this same file (or request) to several of their own friends and so on. Thus F2F networks can grow in size without compromising the users' anonymity.

• Alliance P2P
• Freenet from 0.7 up
• GNUnet with its "F2F topology" option
• Turtle F2F
• WASTE

References

1. ^  Watters, P.A., Martin, F. & Stripf, S. (2005). Visual steganalysis of LSB-encoded natural images. 3rd IEEE International Conference on Information Technology and Applications, Sydney, Australia.

See also

• Anonymity application
• Comparison of file sharing applications
• Secure communication
• Dining cryptographers protocol
• Friend-to-friend networks
• anoNet - anoNet

Hypothetical or defunct networks

• Crowds - Reiter and Rubin's system for "blending into a crowd"
• Invisible IRC Project - anonymous IRC.
• Infrastructure for Resilient Internet Systems
• Mnet - a distributed file system.

External links

• Anonymous-p2p.org
• Planet Peer Board - discussion on anonymous P2P
• - a wiki about various anonymous P2P applications
• A Survey of Anonymous Peer-to-Peer File-Sharing
• Models for Anonymous-p2p Dr. Fabio Dianda - CNR - Italy
• anoNet
• Cashmere : resilient anonymous routing